In contrast to splash type lubrication systems, many of today's machines employ pressurized lubrication systems for ensuring adequate machine part lubrication. In some splash lubrication systems, a viewing glass is used to assure adequate levels of lubricants. With pressurized systems, however, where lubricant is forced through interconnecting passageways, the flow of lubricant is not easy to perceive. Some pressurized systems provide an atomized stream of lubricant to be discharged into a viewing glass. As will be appreciated, an atomized stream of lubricant against the viewing glass, in a position removed from the immediate working area, is not readily conspicuous to the operator. Accordingly, if something should affect the flow of lubricant in such a system, an operator may not quickly envision that lubricant is not being distributed as required. Thus, with today's increasing machine speeds, there is an increasing need for an indicator which allows an easy and quick evaluation of lubricant flow through the pressurized system.